Download
1 / 20
200 likes | 317 Views
Stroke & its consequences. Patient WW Medical history: History of high blood pressure (hypertension) Massive Stroke in Right Hemisphere Behavioral changes: Partially paralyzed on left side. Poor emotional control and judgment. Unaware of his illness (anosognosia).
E N D
Stroke & its consequences Patient WW • Medical history: • History of high blood pressure (hypertension) • Massive Stroke in Right Hemisphere • Behavioral changes: • Partially paralyzed on left side. • Poor emotional control and judgment. • Unaware of his illness (anosognosia). • WW was Woodrow Wilson, 28th US President of USA Special thanks to Chris Rorden, U. South Carolina
Similar cases exist today • Sen Tim Johnson (D-South Dakota) • An hemorrhagic stroke (arteriovenous malformation)
Stroke Stroke is a leading cause of disability. In western world: • Heart Disease • Stroke (10% of deaths worldwide) • Cancer In USA alone • 500,000 people suffer stroke per year • 150,000 people die of stroke per year • 4 million living with stroke • $30 billion in health care costs • 2/3 of strokes in people > 65 y-old
types of stroke Ischemic (80%): the brain artery is clogged (aka obstructive) Haemorrhagic (20%): the brain artery ruptures: bleeding emobolic thrombotic - Some are transitory ischemic attacks (TIA). - ‘Infarct’: Dead tissue following stroke
acute +3days CT T2 MRI • Lesions look different depending on: • How old the lesion is: acute vs. 3 days old • Type of scan (CT, MRI) • Example of Stroke:
newer MRI protocols • Diffusion-weighted imaging • Strokes show up immediately. • Shows permanent white-matter damage.
Imaging Infarcts • MRA (Magnetic Resonance Angiography): Xray MRI MRA stroke MRA
Obstructive strokes: treatment • Treatment: • Counterindicated for haemorrhagic strokes • Prevention of all strokes • Control blood pressure • No smoking • Reduce cholesterol • stent
Neuronal death in stroke • Obstruction • Reduction of O2 & glucose • Na/K pump stops working: • Increase in action potentials • Release of glutamate • Open Na channels -> Na rushes in -> so does water -> swelling • open Ca channels -> activate enzymes -> lesion cell
Stroke: Consequences • As always, it depends on which brain area is affected Example: • Haemorraghic Stroke: It usually lesions orbitofrontal cortex
Haemorrhagic strokes aneurism: a sac-like protrusion of an artery caused by a weakened vessel wall • aneurysm ruptures bleeding • Symptoms: • Really bad headache . • Throwing up • Other neurological symptoms • Treatment: Surgery to clip aneurysm • Consequences: Orbitofrontal lesion (OFC) • Symptoms: • Changes in personality • This is true also of lesion of OFC lesion by other mechanisms (trauma, dementia)
orbitofrontal lesion • symptoms • Social disinhibition • Poor emotion regulation • Denial of deficit • Inability to navigate the social world • Anatomy • Orbitofrontal Cortex • Amygdala
Visual Areas for recognizing objects Lesion stimulus Activation in fMRI in healthy adults
Visual brain area for Color perception Cerebral Achromatopsia: bilateral damage to V4
Area important for speech • Left frontal cortex • Non-productive aphasia (broca’s aphasia) • Also brought about by dementia that affects same area • http://psych.rice.edu/mmtbn/
Hippocampus • Memory deficit • But so does Alzheimer’s disease
In sum • Two types of stroke • Ischemic • Haemorraghic Behavioral consequences are determined by location of lesion!
Ischemic Strokes Major Arteries Carotid Anterior Cerebral Middle Cerebral Posterior Cerebral
Occlusion of middle cerebral artery (MCA) • embolism travels up carotid artery • MCA supplies lateral bank of cortex (image from strokecenter.org) • Damages regions near superior temporal sulcus (sylvian fissure) (figure shows regions damaged in 24 MCA patients, Mort et al. 2003)
